undecidable

Many word problems are undecidable based on the Post correspondence problem.

Even more difficult are the undecidable problems, such as the halting problem.

Even undecidable problems, like the halting problem, can be used.

The cause of his death is an undecidable problem.

It follows immediately that the uniform word problem is also undecidable.

There are many known examples of undecidable problems from ordinary mathematics.

Robinson established in 1949 that the theory of fields is undecidable.

The new statement was undecidable, not deducible from the set within him.

It is undecidable who would have copyright on a block, which has several meanings.

We have previously shown, however, that the halting problem is undecidable.

Decision problems become harder to answer or completely undecidable.

There are two distinct senses of the word "undecidable" in contemporary use.

But was there at least some way to tell in advance which statements were undecidable, not worth bothering with?

Many problems of mathematics have been shown to be undecidable after these initial examples were established.

As with many undecidable questions, one can still attempt to give useful approximate solutions.

The halting problem is historically important because it was one of the first problems to be proved undecidable.

Determining whether a subprogram may have a side effect is very difficult (indeed, undecidable).

For more expressive formalisms, this problem can be harder, or even undecidable.

Would the grinding go on forever, meaning the statement was indeed undecidable, or did you simply need to be more patient?

He produced many other drawings of impossible objects, sometimes with the entire drawing being an undecidable figure.

A statement like this could not be undecidable; it had to be either true or false.

Most of these questions, however, are undecidable, meaning that the function in question cannot be calculated mechanically.

The rank problem is undecidable for word hyperbolic groups.

They showed that there is no such algorithm, thus the problem is undecidable in the general case.

In fact, every consistent extension will be essentially undecidable.